1. Field of the Invention
The invention relates generally to a method and system for the computerized registration of images obtained from two different modalities, and in particular, computerized registration of radionuclide images with radiographic images. Specific applications are given for the automated registration of radionuclide lungs scans with chest radiographs.
2. Discussion of the Background
Computer-aided diagnosis (CAD) has potential to become a valuable tool for detecting subtle abnormalities in medical imaging and, in particular, chest radiographs and radionuclide images. Chest radiographs and radionuclide images (nuclear medicine scans) such as ventilation/perfusion (V/Q) scans are used to visually evaluate pulmonary embolism, chronic lung disease, heart disease and pre-operative lung function. Currently, radiologists assess correlation between the images (exams) visually by looking at three separate types of film images. It would be beneficial for the radiologist to be able to more accurately match V/Q defects to radiographic findings.
This patent application presents a method and system for the computerized registration of radionuclide images with radiographic images. Specific applications are given for the automated registration of radionuclide lungs scans with chest radiographs. Techniques include contouring the lung regions in each type of chest image, scaling and registration of the contours based on location of lung apices, and superimposition after appropriate shifting of the images. The method in the example given yields a system that spatially registers and correlates digitized chest radiographs with V/Q scans in order to correlate V/Q functional information with the greater structural detail of chest radiographs.